Pharmaceutically active agents are generally formulated as solid or liquid dosage forms for administration. Such dosage forms generally comprise the active agent combined with excipients to form materials that may be conveniently and reliably administered to a patient in need of such therapy, and following administration, the active agent is absorbed and distributed in the patient in a way that leads to good efficacy and safety.
Cationic polymers have previously been used for extended or controlled release of active agents near the site of delivery. Some cationic polymers have been evaluated for this purpose and in some cases have been referred to as “mucoadhesive.” Examples of cationic mucoadhesive excipients include chitin, chitosan, and amino-substituted polyacrylates and polymethacrylates.
Dextrans having an amine substituent that possesses at least two amino groups and a hydrophobic group have been described. The polymers are used in compositions for gene therapy.
Compositions that consist of complexes of copolymers and adenoviruses that are not bound by covalent bonds and have been used to improve delivery and transgenic expression of the adenovirus in cells have been described. The copolymers consist of a cationic polymer (such as polyethyleneimine [PEI], polylysine, diethylaminoethyl [DEAE] dextran, and derivatives) and a nonionic polymer (such as polyethylene glycol [PEG] and derivatives).
Amino-acid substituted dextrans useful for systemic delivery of therapeutic agents have been described. Amino-dextrans for use in forming colloidal particles have also been described.
What is desired is a cationic dextran derivative that would be suitable for use in a wide variety of formulations.